Automated forming of cast polyurethane

ABSTRACT

Cast polyurethane parts for shoes or other items may be formed in an automated fashion. A dispensing mechanism may dispense a predetermined amount of a liquid phase polyurethane mixture onto a flat surface face of a mold. A dispersal mechanism may distribute the liquid phase polyurethane mixture over the flat surface face of the mold to fill at least one cavity in the form. A vacuum may be applied to remove air bubbles from the liquid phase polyurethane mixture. Excess liquid phase polyurethane mixture may be removed from the flat surface face of the mold using a flexible blade that contacts and moves across the flat surface face. One or more conveyance mechanism may transport molds through the desired stages of a system and/or method in accordance with the present invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority to, pendingU.S. Nonprovisional application Ser. No. 13/833,543, filed Mar. 15,2013, titled “Automated Forming of Cast Polyurethane,” having, theentire contents of which are hereby incorporated by reference.

FIELD

The present invention relates to materials, systems, and/or methods forforming cast polyurethane. More particularly, the present inventionrelates to the automated production of cast polyurethane parts for usein shoes and other items.

BACKGROUND

Cast polyurethane is a useful component of many products, such as shoes.Cast polyurethane possesses properties, such as being relatively pliableand light weight, that make useful for constructing various items and/orcomponent parts of items. The ability to form polyurethane into adesired shape, size, and configuration desired is particularly useful.However, the known processes for forming cast polyurethane areundesirably inefficient and wasteful. For example, in conventional castpolyurethane forming methods workers using straight edges, squeegees, orthe like must repeatedly scrape the liquid phase polyurethane todistribute the polyurethane within a mold cavity and remove excesspolyurethane from the face of the mold. The excess polyurethane removedby manual scraping is typically unable to be reused, leading toundesirable waste. In addition to repeated and labor intensive manualscraping steps that waste liquid polyurethane, the liquid polyurethanemust be repeatedly subjected to a vacuum force to draw air bubbles outof the liquid. Typically, a scraping step must be performed both beforeand after each vacuum step, which further increases the labor cost andmaterial waste of forming cast polyurethane. Further, the irregularitiesof a largely manual process of forming cast polyurethane can lead toirregular product quality, unpredictable product performance, andexcessive rejections by quality control evaluation.

SUMMARY

Polyurethane is a useful material utilized in a variety of products suchas shoes and, more particularly, athletic shoes. Polyurethane may beused for a variety of purposes in an athletic shoe, such as, but notlimited to, soles, midsoles, uppers, structural supports, functionalelements on a shoe upper, decorative components, and the like.Polyurethane components in a shoe may be formed using molds to retain aliquid phase polyurethane mixture for curing to create a castpolyurethane part. Cast polyurethane may be referred to as “CPU.”Forming cast polyurethane has traditionally been a labor-intensiveprocess. However, manually forming cast polyurethane for shoe parts canlead to irregular and unpredictable characteristics for the resultingparts, as well as requiring additional training and other precautionsfor the workers involved in forming the cast polyurethane.

Accordingly, systems and methods in accordance with the presentinvention for the automated forming of cast polyurethane are describedherein. Cast polyurethane may be formed using a mold or form with one ormore cavities corresponding to the size and shape of the castpolyurethane part to be formed. The mold may have a substantially flatsurface face below which the cavity extends. A mold used in accordancewith the present invention may move through a system in accordance withthe present invention on a conveyance mechanism, such as a sequence ofpushers and rollers, a conveyor belt, or any other conveyance mechanismat a predetermined rate or rates. The mold may pause and/or be retainedin place at various stations in order for operations to be performed onthe polyurethane and/or the mold. A mold may be retained in place usingstops, blocks, rails, clamps, or other mechanisms that retain a mold inplace while operations are performed on the mold and/or polyurethane onor within the mold. The rate at which an individual mold progressesthrough a system may vary based upon the portion of the system that themold is encountering, quality control demands, performance requirements,and the like. A mixing station may combine the component materials ofliquid polyurethane, an isocyanate and a polyol, as part of orimmediately prior to a liquid phase polyurethane mixture dispensingsystem. A liquid phase polyurethane mixture dispensing system maydispense liquid polyurethane into the cavity and/or onto thesubstantially flat surface face of a mold in accordance with the presentinvention. Various approaches may be used to attain a desireddistribution and amount of polyurethane over the face of a mold, such asby using nozzles having a desired distribution pattern that movesdispensers relative to the face of a mold to dispense polyurethane overthe face in a desired pattern. For example, a dispensing nozzle maydistribute liquid polyurethane in a predetermined amount, at apredetermined rate, and/or in a predetermined pattern so as to fill thecavity of the mold substantially completely with little or no excessliquid polyurethane beyond the amount needed to fill the cavity. Bycontrolling the amount of liquid phase polyurethane mixture dispensedand/or the pattern in which the liquid phase polyurethane mixture isdispensed over the flat surface face of the mold to correspond to the atleast one cavity in the mold, the waste of polyurethane may be reducedand the quality of cast polyurethane parts produced may be improved ascompared to prior polyurethane processes.

A system in accordance with the present invention may further dispersepolyurethane over the face of a mold, for example by using moving air tospread the liquid phase polyurethane mixture across the face of the moldafter the liquid phase polyurethane mixture has been deposited. Movingair may be applied by a blower, an air knife, a compressed air source,or other mechanism. Air may be applied at a predetermined angle orangles that serves to move or spread polyurethane in a desireddirection(s) within a cavity and/or on the flat surface face of themold. Additionally/alternatively, a vibration unit such as a shake tablemay be used to disperse liquid phase polyurethane mixture within acavity and/or on the flat surface face of the mold. A vacuum system mayapply a vacuum to the flat surface face of the mold and the liquid phasepolyurethane mixture to extract air bubbles from the liquid phasepolyurethane. The vacuum system may interface with the mold to establisha substantially air tight seal, thereby permitting an extremely lowpressure to be applied to the liquid polyurethane extracting air bubblesfrom the liquid polyurethane in a single application rather thanmultiple applications.

A system in accordance with the present invention may further provide aflexible blade, such as a squeegee, to force the liquid phasepolyurethane mixture into the cavity of the mold and/or to remove excessliquid polyurethane from the face of the mold. The mold may be retainedin place while the flexible blade contacts and moves across the flatsurface face of the mold. Alternatively, the flexible blade may bepositioned such that a conveyance mechanism moves the mold beneath theflexible blade such that the flat surface face of the mold contacts atleast the edge of the blade as the mold is moved to cause the flexibleblade to cross the flat surface face. Various manners of biasingmechanisms, such as springs, pneumatic cylinders, and the like, may beused to bias the flexible blade and/or the mold and/or conveyancemechanisms towards one another to adequately engage the flexible bladeagainst the flat surface face of the mold. A flexible blade may engagethe face of a mold at a predetermined angle or angles that is the sameas, different from, or related to the angle or angles at which movingair is applied. A flexible blade may, for example, be applied at anangle or in a direction opposing the direction of application of themoving air, which may aid in the uniform distribution of liquidpolyurethane in a mold. A cleaning unit may clean residual liquidpolyurethane from the flexible blade at appropriate intervals, such asafter each use, every five uses, every ten minutes, etc.

In various implementations of systems and methods in accordance with thepresent invention, these various components may be ordered in differentways, duplicated, or omitted. Further, heating or other curing devicesmay be used to facilitate the formation of solid polyurethane from theliquid phase polyurethane mixture used in accordance with the presentinvention. For example, an oven, heating mat, heating table, heat press,or other type of heating device may be used to heat a mold to facilitatepartial or complete curing of the liquid phase polyurethane mixture inthe cavity of the mold.

Systems and/or methods in accordance with the present invention maypre-clean molds prior to use (by scrubbing or air blowing, for example),treat molds with release agents or the like, inspect molds prior to use,etc. Further, in systems and methods in accordance with the presentinvention equipment may be provided to remove a cured polyurethane piecefrom a mold and to clean a form for re-use, if desired.

Methods in accordance with the present invention may convey molds havingat least one cavity extending below a flat surface face of the moldthrough a series of stations or components of a system to form castpolyurethane molds conveyed may be moved so as to maintain the flatsurface face in a substantially horizontal orientation. A predeterminedamount of a liquid phase polyurethane mixture may be dispensed in apredetermined pattern onto the flat surface face of the mold and/or intothe at least one cavity of the mold. The predetermined amount of liquidpolyurethane mixture dispensed may correspond to the volume of at leastone cavity, and the predetermined pattern in which the liquid phasepolyurethane mixture is dispensed may correspond to the configurationand location of the at least one cavity of the mold. The dispensedliquid phase polyurethane mixture may be dispersed, for example usingmoving air, to facilitate filling of the at least one cavity of themold. A vacuum may be applied to the liquid phase polyurethane mixtureto extract bubbles from the liquid phase polyurethane mixture. Excessliquid phase polyurethane mixture may be removed from the flat surfaceface of the mold using a flexible blade that contacts and moves acrossthe flat surface face of the mold. The flexible blade may beperiodically cleaned to remove liquid phase polyurethane mixture.Additional steps, such as mold preparation, polyurethane curing,de-molding cast polyurethane parts, and the like may also beincorporated in such a method.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 illustrates a schematic diagram of an example system inaccordance with the present invention.

FIG. 2 illustrates one example of a dispensing system in accordance withthe present invention.

FIG. 3 illustrates a further example of a dispensing system inaccordance with the present invention.

FIG. 4 schematically illustrates an example of a dispensing nozzledispensing liquid polyurethane mixture onto a mold in accordance withthe present invention.

FIG. 5 illustrates an example of a mold after the dispensing of apolyurethane mixture in accordance with the present invention.

FIG. 6 illustrates an example of a mold after dispensing of apolyurethane mixture but before the dispersal of polyurethane across theflat surface face of the mold.

FIG. 7 illustrates an example of polyurethane mixture dispersed across amold in accordance with the present invention.

FIG. 8 illustrates an example of a mold with polyurethane mixture inaccordance with the present invention while a vacuum is applied toremove bubbles.

FIG. 9 illustrates an example of a mold in accordance with the presentinvention after polyurethane mixture has been deposited on its face,dispersed across the face, experienced a vacuum, and the excesspolyurethane mixture has been removed.

FIG. 10 illustrates an example of a method in accordance with thepresent invention for forming cast polyurethane.

FIG. 11 illustrates an example of a biased flexible blade that may beused in conjunction with forming cast polyurethane in accordance withthe present invention.

FIG. 12 illustrates an example of a vibrational system that may be usedto disperse a liquid polyurethane mixture in accordance with the presentinvention.

FIG. 13 illustrates an example of a blade cleaning apparatus that may beused to clean a flexible blade used in forming cast polyurethane inaccordance with the present invention.

FIG. 14 illustrates an example of adhering a sheet of material to castpolyurethane formed in accordance with the present invention.

FIG. 15 illustrates a schematic diagram of another exemplary system inaccordance with the present invention.

DETAILED DESCRIPTION

The present invention provides systems and methods for forming castpolyurethane. While the present invention is described herein forexamples of forming cast polyurethane for use as parts in constructingathletic shoes, the systems and methods in accordance with the presentinvention may be used for forming cast polyurethane parts for use inother types of shoes or even for products other than shoes. Theparticular formulation, type, physical properties, chemical properties,etc. of polyurethane desired may vary based upon the properties desiredfor the product ultimately incorporating the polyurethane part and thepurpose of the cast polyurethane part in the finished product. Differenttypes of polyurethane parts may benefit from different types of moldmaterials, dispensing mechanisms, dispersing mechanisms, curingtechniques, and the like. These variations are within the scope of thepresent invention, although only particular examples are describedherein.

Referring now to FIG. 1, a system 100 for forming cast polyurethane isschematically illustrated. FIG. 1 does not depict example system 100 toscale. System 100 is merely one general example of various componentsthat may be used for forming cast polyurethane in accordance with thepresent invention. Other configurations, combinations, arrangements,additions, modifications, and/or omissions of the example componentsillustrated in FIG. 1 may be made. While FIG. 1 illustrates a linearsystem 100, in any implementations other configurations may bedesirable. For example, a system for forming cast polyurethane inaccordance with the present invention may effectively form a loop thatmoves molds repeatedly through a process of forming cast polyurethaneparts and then prepares the molds for re-use. Systems in accordance withthe present invention may also vary from the example system 100 shown inFIG. 1 in that components may be added, omitted, or modified beyond theexamples illustrated in system 100. In some examples of systems inaccordance with the present invention, components may operateindependently from one another. Further, a system in accordance with thepresent invention may provide various paths for forming a castpolyurethane part, with a part in processing moving to the nextcomponent most available (for example, with the shortest queue of partsawaiting processing) rather than simply proceeding in a substantiallylinear fashion as described in the examples herein.

As depicted in FIG. 1, a mold 120 may be moved along a conveyancemechanism 110 to permit system 100 to form a cast polyurethane part.Mold 120 may be constructed of aluminum or any other material with theresiliency, durability, thermodynamic properties, etc., required for theforming of a particular type of cast polyurethane. Mold 120 may, ifdesired, be preheated or prechilled to a desired temperature for optimalcast polyurethane forming conditions. FIG. 1 does not depict any type ofform preparation component, but such components may be a part of asystem in accordance with the present invention. Mold 120 may have atleast one cavity 122 extending beneath a flat surface face 124. Whileonly a single cavity 122 is illustrated within mold 120 in the exampleof FIG. 1, additional cavities may be present. Cavity 122 may ultimatelycorrespond to the size and shape of the desired cast polyurethane part.Conveyance mechanism 110 is shown as a conveyor belt in the example ofFIG. 1, but may be any type of conveyance mechanism, such as chain drivesystem, a system of rollers, a pusher system, or any other device thatmoves mold 120 through system 100 may transport mold 120 as indicated byarrow 101 through system 100. FIG. 15, which is described further below,depicts an example of a system in accordance with the present inventionwherein a pusher and roller system is used to convey molds.

While the schematic example of FIG. 1 is illustrated in a substantiallylinear fashion, a system 100 in accordance with the present inventionmay be organized in a circle, square, vertically, a non-linear fashion,or in any other configuration with different constituent parts of thesystem 100 arranged as appropriate for the particular application of theinvention. For example, instead of a single conveyance mechanism 110,multiple conveyance mechanisms may be used to transport a mold 120 tovarious stations of a system in accordance with the present invention,potentially with a mold such as mold 120 spending longer amounts of timein some portions of the system rather than others, such as an extendedamount of time in an oven for curing of polyurethane. In FIG. 1 a firststop 102, a second stop 104, and a third stop 106 are illustrated. Stops102, 104, 106 may comprise any type of mechanism or structure thatretains a mold 120 in place for processes to be performed upon the moldand/or polyurethane on/in the mold.

A liquid phase polyurethane mixture dispensing system 130 may apply apredetermined amount of a liquid phase polyurethane mixture into thecavity 122 of a mold 120 and/or onto the flat surface face 124 of mold120 in a predetermined dispersal pattern when conveyance mechanism 110moves mold 120 into an appropriate position. As indicated by axes 139,dispensing mechanism may be capable of moving in three dimensions todistribute a liquid phase polyurethane mixture on a form in a desiredpattern appropriate for the part to be formed. The amount of liquidphase polyurethane mixture dispensed and/or the pattern in which theliquid phase polyurethane mixture is dispensed may correspond to thesize and/or location of cavity 122, in order to facilitate the efficientfilling of cavity 122. Conveyance mechanism 110 may pause when mold 120is appropriately positioned, or a mold may be retained by stopper 102.Alternatively or additionally, a mold 120 may be moved off of conveyancemechanism 110 and into position for dispensing system 130, or dispensingsystem 130 may dispense a liquid phase polyurethane mixture into thecavity 122 and/or upon the flat surface face 124 of mold 120 as mold 120is moved by conveyance mechanism 110.

Dispensing component 130 may comprise a nozzle 132 that receives liquidphase polyurethane mixture for dispensing. Due to the chemicalproperties of polyurethane, a reservoir may comprise multiplecompartments that contain different components, typically at least anisocyanate and a polyol, that are mixed as needed for dispensing by, forexample, nozzle 132. For example, a first compartment 134 may contain anisocyanate and a second compartment 135 may contain a polyol. A firsttube 136 may transport the isocyanate from the first compartment 134,and second tube 137 may transport the polyol from the second compartment135, although additional compartments and/or tubes may be used foradditional components or additives such as color agents, that may bedesired. First tube 136 and second tube 137, as well as any additionaltubes, may transport components to a mixing unit 131 that mixes thecomponents (for example, by agitation, stirring, etc.) to form a liquidphase polyurethane mixture. The resulting liquid phase polyurethanemixture may have materials present in addition to merely polyurethane,such as desired additives, unreacted isocyanate and/or polyol, and/orimpurities. Alternatively, first compartment 134 and second compartment135 may dispense materials to mixing unit without tubes, or alreadymixed liquid polyurethane may be provided from a reservoir to adispensing nozzle 132. As explained more fully below, dispensing station130 and nozzle 132 may distribute a predetermined amount of liquid phasepolyurethane mixture in a dispersal pattern into the cavity 122 and/orover the flat surface face 124 of mold 120. These dispersal patterns maybe selected, in part, based upon the size and shape of the cavity 122 tobe filled with liquid phase polyurethane mixture by system 100 in orderto reduce the waste of polyurethane in the process of forming castpolyurethane. While a single cavity 122 is illustrated within a singlemold 120 in FIG. 1, in practice a single mold may provide multiplecavities for use in forming cast polyurethane in accordance with thepresent invention.

A dispersal mechanism 138 may distribute the dispensed liquid phasepolyurethane mixture in an appropriate pattern within the cavity 122and/or over the flat surface face 124 of mold 120. Dispersal mechanism138 may comprise, for example, an air blower or an air knife that usesmoving air to distribute the dispensed liquid phase polyurethane mixtureacross the flat surface face 124 of the mold 120. An alternative and/oradditional dispersal mechanism 138 may be a vibrational unit, such as ashake table. Dispersal mechanism 138 may be omitted entirely if nozzle132 or other liquid phase polyurethane mixture dispensing mechanismdistributes liquid polyurethane over the flat surface face 124 of mold120 in a manner that is acceptable to adequately fill the cavity 122used to form an eventual cast polyurethane part. Dispersal mechanism 138may be part of the dispensing component 130, but dispersal mechanism 138may comprise an entirely separate component of system 100. Further,dispersal mechanism 138 may constitute a plurality of similar ordifferent mechanisms, such as multiple air knives and/or vibrationalunits, that operate to distribute liquid polyurethane across a flatsurface face 124 of a mold 120. A dispersal mechanism 138 such as ablower, air knife, or the like may be oriented at a distance from theflat surface face of, for example, between 20 and 40 millimeters, mayproduce an air speed of between 5 and 20 meters per second, and may bepositioned at an angle 139 of between 45 and 90 degrees relative to theflat surface face 124. The angle at which moving air approaches thedispensed liquid phase polyurethane mixture and the flat surface face124 of a mold 120 may serve to move the liquid phase polyurethanemixture in a predetermined direction and distance within the cavity 122and/or over the face 124 of a mold 120. Such movement of liquidpolyurethane may be accounted for in determining the dispensing patternused by dispensing component 130 in order to efficiently fill the cavity122 with the liquid phase polyurethane mixture.

A vacuum system 159 may comprise a vacuum generator 152 that applies areduced air pressure to the liquid phase polyurethane mixture on a mold120 via a vacuum chamber 150 to extract air bubbles from the liquidphase polyurethane mixture. While the example schematic of FIG. 1illustrates the vacuum chamber 150 located after the dispersal mechanism138 and before flexible blade 140 when a mold 120 is transported byconveyance mechanism 110 in the direction indicated by arrow 101, otherconfigurations and/or orders of components may be used. A hose 154 mayconnect a vacuum-generating unit 152 to a vacuum chamber 150. Hose 154may comprise a vacuum hose or duct in many implementations of thepresent invention. A vacuum chamber 150 may move vertically as indicatedby axis 151 to engage a mold 120 with an opening or mouth shaped to matewith mold 120 to provide a reasonably air-tight seal over a mold 120 tofacilitate the extraction of air bubbles from the liquid phasepolyurethane mixture on mold 120 and/or in cavity 122 of mold 120.Alternatively/additionally, vacuum chamber 150 may form a seal with thesurface underlying mold 120, which may comprise a conveyance mechanism110 such as a conveyor belt, a table that retains a mold 120 at thevacuum station, etc. Vacuum chamber 150 may form a temporary seal with amold 120 while mold 120 is retained in position by stop 104, and may useseals, gaskets, clamps, etc. to attain a sufficiently air tight seal.Vacuum chamber 150 may be moveable as indicated by axis 151 so as toengage and disengage a mold 120 during the process. The duration ofapplication and the power of the vacuum applied may vary. In oneexample, a vacuum may be applied for a total of thirty seconds, with apressure of 10 torr attained in 13.5 seconds.

In the present example illustrated in FIG. 1, as conveyance mechanism110 moves a mold 120 through system 100, after the liquid phasepolyurethane mixture has been distributed over the flat surface face 124of mold 120 and after bubbles have been removed from the liquid phasepolyurethane mixture by the vacuum 150, a flexible blade 140 may be usedto remove excess remaining liquid phase polyurethane mixture from theflat surface face 124 of mold 120 and/or to force the liquid phasepolyurethane mixture into cavity 122 extending below flat surface face124 of mold 120. Flexible blade 140 may comprise, for example, asqueegee within a holder 142. Holder 142 may be operable to move in atleast two dimensions, as indicated by axes 149, in order to contactflexible blade 140 to flat surface face 124 of mold 120 and to move theflexible blade 140 over flat surface face 124 of mold 120 while mold 120is retained by stopper 106. Alternatively, holder 142 may maintain thepositioning of flexible blade 140 relative to the conveyance mechanism110 and/or a mold 120 being moved by conveyance mechanism 110 to permitmold 120 to be moved so as to bring flexible blade 140 into contact withand across flat surface face 124 of mold 120. In the example illustratedin FIG. 1, blade 140 engages the flat surface face 124 of mold 120 at anangle 149 less than ninety degrees, but angles of other magnitudesand/or varying magnitudes may be used in accordance with the presentinvention. Further, multiple flexible blades 140 may be used to provideadequate coverage of the entire flat surface face 124 of a mold 120, ora single flexible blade 140 may be used over different locations inmultiple passes to provide adequate removal of excess liquid phasepolyurethane mixture from a flat surface face 124. A flexible blade 140may optionally move the liquid phase polyurethane mixture in theopposite direction that moving air from a dispersal mechanism 138 movedthe liquid polyurethane mixture to further assure an even distributionof the liquid phase polyurethane mixture within a cavity 122.

One or more biasing mechanisms may bias flexible blade 140 or mold 120(or conveyance mechanism 110 carrying mold 120) toward one another toengage blade 140 against flat surface face 124 of mold 120. Biasingmechanisms may comprise springs, pneumatic cylinders, etc.Alternatively, a holder 142 may rigidly maintain a flexible blade 140 ina position that adequately engages flat surface face 124 of mold 120without a need for a biasing mechanism.

In various examples of systems and methods in accordance with thepresent invention, a cleaning mechanism may be optionally provided toremove remaining liquid phase polyurethane mixture from a flexible blade140. A variety of cleaning mechanisms or combinations of cleaningmechanisms may be used in accordance with the present invention. Forexample, a cleaning mechanism may be used that moves to a flexible blade140 that remains stationary in its position relative to the remainder ofsystem 100 after a mold 120 has been scraped by blade 140.Alternatively, a flexible blade 140 may be moved to be engaged by acleaning mechanism and then repositioned for the next operation of theflexible blade 140. Flexible blade 140 may be constructed of a varietyof materials, such as artificial or natural rubbers, flexible metals,composites, and the like. Depending upon the types of materials used fora flexible blade 140, different types of cleaning mechanisms constructedof different materials may be selected. For example, a cleaningmechanism may utilize one or more brush that engages flexible blade 140.A brush or brushes may optionally rotate to facilitate in removingremaining liquid phase polyurethane mixture from a flexible blade 140.Another example of a cleaning mechanism is a nozzle that appliescompressed air at a predetermined force, rate, and/or angle to blowliquid polyurethane from the flexible blade 140. By way of furtherexample, water or other solvents may be sprayed to remove liquidpolyurethane from a flexible blade 140, or a flexible blade 140 may besubmerged partially or entirely in a bath of water and/or anothersolvent to remove excess liquid phase polyurethane mixture. Yet anotherexample of a possible cleaning mechanism is a vibrating mechanism thatwill induce vibrations to a flexible blade 140 to vibrate residualliquid phase polyurethane mixture from the flexible blade 140. Further,multiple types of cleaning mechanisms may be used simultaneously and/orserially to obtain a desired level of cleanliness of a flexible blade140. In one example, one or more air nozzles may spray air at an anglealong the length of blade 140 while one or more rotating circularbrushes engage along the length of the blade 140. For example, aflexible blade 140 may be moved to insert into a solvent bath, afterwhich flexible blade 140 may be vibrated and engaged by a water spray.After being engaged by a water spray, a flexible blade 140 may beengaged by rotating brushes to finish the cleaning of the flexibleblade. Depending upon the type of flexible blade used, the properties ofthe liquid phase polyurethane mixture dispensed in accordance with thepresent invention, and/or the cleanliness tolerances required for aparticular application of the present invention, any number of cleaningmechanisms may be used on a flexible blade 140 at any desiredregularity. For example, a flexible blade 140 may be cleaned after eachuse, after every five uses, at hour intervals, or at any otherregularity appropriate for a particular use of systems and methods inaccordance with the present invention.

Conveyance mechanism 110 may ultimately transport a mold 120 along thedirection indicated by arrow 101 to additional components, some of whichare described more fully below. For example, additional stations of asystem in accordance with the present invention may pre-cure a liquidphase polyurethane mixture, cure the liquid phase polyurethane mixture,apply additional components such as textiles to the polyurethane, removecast polyurethane from a mold, clean molds, apply mold release agents tomolds for future use, prechill or pre-heat molds for future use, qualitycontrol or inspection stations for cast polyurethane and/or molds, etc.

A computing device 190 having a processing unit 191 executinginstructions from a computer readable media 192 may monitor and/orcontrol the operation of one or more component of system 100 viaconnections 198. Computing device 190 may have an output device(s) 194and an input device(s) 196 to permit a human user to evaluate or modifythe performance of system 100. Computing device 190 may be connected toa network 199, thereby permitting various components of system 100and/or computing device 190 itself to be located remotely from othercomponents. Connections 198 and to network 199 may be wireless or wiredand may use any protocol to monitor and/or control system 100 or toprovide/receive information from a human user. Any type of input device196 and output device 194 may be used, such as devices that may functionboth to provide outputs and to receive inputs, such as touchscreens.

Referring now to FIG. 15, a further example of a system 1500 inaccordance with the present invention is illustrated. System 1500 in theexample of FIG. 15 resembles system 100 in the example of FIG. 1, exceptthat system 1500 uses rollers 1510 and at least one pusher 1505 as aconveyance mechanism instead of the conveyor belt 110 shown in theexample of FIG. 1. Other exemplary components depicted in the example ofFIG. 15 may resemble the corresponding exemplary components describedabove with regard to the example of FIG. 1.

Referring now to FIG. 2, a further example of a dispensing mechanism isillustrated. In the example illustrated in FIG. 2, a first nozzle 232dispenses a first stream 212 of a liquid phase polyurethane mixturewhile a second nozzle 233 dispenses a second stream of a liquid phasepolyurethane mixture 213 over a mold 120 and into cavity 122. Thedistance between a nozzle 232, 233 and mold 120 may be selected basedupon the properties desired for the liquid phase polyurethane mixturedistributed in the streams 212, 213, with a shorter distance reducingthe number of bubbles formed in the liquid phase polyurethane mixtureand reducing the spread of each of the liquid phase polyurethane mixturestreams 212, 213 before contacting the mold 120. The example arrangementillustrated in FIG. 2 may, for some examples, attain a satisfactorydistribution of liquid phase polyurethane mixture over the flat surfaceface 124 of mold 120 such that all portions of cavity 122 are engaged,thereby precluding the need to use a dispersal mechanism 138, orreducing the functionality required for such a dispersal mechanism 138.

Referring now to FIG. 3, a further example of a dispensing mechanism inaccordance with the present invention is illustrated. In the exampleshown in FIG. 3, a single nozzle 332 dispenses a stream 312 of liquidphase polyurethane mixture into cavity 122 and/or onto flat surface face124 of mold 120. As indicated in FIG. 3, nozzle 332 may be actuated inboth a first direction 341 and a second direction 342 to facilitate thedistribution of the liquid phase polyurethane mixture over a flatsurface face 124 of mold 120. As indicated by axes 139 in FIG. 1,however, a nozzle such as nozzle 332 may be movable in all threedimensions, allowing nozzle 332 to widely and precisely distribute astream of liquid phase polyurethane mixture within cavity 124. Ifactuated vertically, the distance between nozzle 332 and mold 120 may bevaried during distribution of the liquid phase polyurethane mixture, ifdesired. For some example applications, a nozzle 332 that may beactuated in multiple directions may provide adequate distribution of aliquid phase polyurethane mixture over the surface face 124 of mold 120to adequately engage all portions of cavity 122. If such is the case, adispersal mechanism 138 may potentially be omitted or may be reduced infunctionality.

Referring now to FIG. 4, a further example of a nozzle 432 is shownschematically above a form 120 with a cavity 122. In the example shownin FIG. 4, nozzle 432 may move along two axis, such that nozzle 432 maymove in a first direction 441 and in an opposing second direction 442along a first axis, and nozzle 432 may further move in a third direction443 and in an opposing fourth direction 444 along a second axis.Optionally, nozzle 432 may move along another axis, in this examplecloser or further to mold 120, or may move to tilt at an angle relativeto mold 120. Such mobility of nozzle 432 may permit the dispensing of aliquid phase polyurethane mixture over a surface face 124 and/or into acavity 122 of a mold 120 in an efficient pattern. Further, by preciselycontrolling the amount of polyurethane mixture dispensed by nozzle 432,whether by weight, or by volume, or both, waste of polyurethane may bereduced without impairing the quality of the resulting cast polyurethaneparts due to the precise placement of the liquid phase polyurethanemixture within the cavity 122 of a mold 120.

Referring now to FIG. 5, an example mold 120 with liquid phasepolyurethane mixture 512 dispensed over at least a portion of the flatsurface face 124 and into at least a portion of cavity 122 isillustrated. The example illustrated in FIG. 5 may be attained in any ofa number of fashions, such as, but not limited to, the examplesillustrated in FIGS. 2-4 above. As can be seen from the exampleillustrated in FIG. 5, liquid phase polyurethane mixture 512 extendsbeyond the flat surface face 124 of mold 120, rather than being limitedmerely to cavity 122 corresponding to the part to be formed frompolyurethane. As described herein, further components in accordance withthe present invention may function to distribute liquid phasepolyurethane mixture throughout the cavity 122 of mold 120 and removeany excess liquid phase polyurethane mixture from the flat surface face124 of the mold 120. The amount of liquid phase polyurethane mixturedispensed into cavity 122 may be selected so as to minimize the amountof polyurethane used beyond the minimum necessary to fill cavity 124while also providing a sufficient amount to assure that the cavity 122is fully filled. The precise positioning of liquid phase polyurethanemixture during the dispensing may enable less waste of polyurethanewhile still attaining a complete filling of a cavity 124 with liquidphase polyurethane mixture. The actual amount of liquid phasepolyurethane mixture dispensed relative to the size of a cavity 122 mayvary from that illustrated in FIG. 5, which is for illustrative purposesonly. As also illustrated in FIG. 5, a plurality of bubbles 550 may beintroduced into the liquid phase polyurethane mixture before or duringthe dispensing process. Such bubbles 550 may undermine the consistencyand structural qualities of the finished cast polyurethane product and,therefore, may be removed prior to curing the polyurethane as describedherein.

Referring now to FIG. 6, a mold 120 having therein a cavity 122 isillustrated. Mold 120 and cavity 122 are merely examples. The cavity 122illustrated in FIG. 6 may correspond to any type of part desired for ashoe or other item. The example shown in FIG. 6 is exemplary only, withactual molds 120 and actual cavities 122 used in accordance with thepresent invention being able to take any of a variety of forms,depending upon the item to be ultimately manufactured and the desiredsize, shape, properties, etc. of the ultimately formed cast polyurethanepart. As indicated by arrow 101, mold 120 may be moving as indicatedthrough a system such as system 100. As shown in the example of FIG. 6,a single dispensing nozzle 132 has applied a predetermined amount of aliquid phase polyurethane mixture 512 in a predetermined pattern overthe flat surface face 124 of mold 120. Both the amount and pattern usedto dispense the liquid phase polyurethane mixture 512 corresponds to thesize and configuration of cavity 122. Any of a variety of dispensingmechanisms, such as but not limited to those described with regard toFIGS. 2-4 may be used in accordance with the present invention. As canbe seen in the example of FIG. 6, a predetermined amount of liquid phasepolyurethane mixture 512 has been dispensed in a pattern that placesmost of the dispensed liquid polyurethane within cavity 122. As alsoshown in FIG. 6, dispensed liquid phase polyurethane mixture 512 mayhave a large number of bubbles 550. As shown in FIG. 6, the direction ofmovement 101 by conveyance mechanism 110 has not yet brought mold 120 tothe dispersal mechanism 138.

Referring now to FIG. 7, a mold 120 with a cavity 122 therein isillustrated after a dispersal mechanism 138 has distributed the liquidphase polyurethane mixture 712 over the flat surface face 124 of mold120. As can be seen from comparing the dispensed liquid phasepolyurethane mixture 512 in FIG. 6 to the dispersed liquid phasepolyurethane mixture 712 in FIG. 7, dispersal mechanism 138 hasdistributed the liquid phase polyurethane mixture across the flatsurface face 124 of mold 120 such that the entirety of cavity 122 iscovered without a large amount of the liquid phase polyurethane mixtureneedlessly distributed over the flat surface face 124 of mold 120. Asdescribed above, dispersal mechanism 138 may comprise a blower, airknife, vibration unit, or other types of mechanisms that distributesliquid phase polyurethane mixture over the flat surface face 124. As canbe further seen in the example illustrated in FIG. 7, the liquid phasepolyurethane mixture has been moved from the pattern in which it wasdispensed (for example as illustrated in FIG. 6) to distribute theliquid phase polyurethane mixture within cavity 122. As also shown inthe example of FIG. 7, at least some of the distributed liquid phasepolyurethane mixture 712 extends beyond the cavity 122 and onto the flatsurface face 124 of the mold 120.

Referring now to FIG. 8, a vacuum chamber 150 has engaged a mold 120and/or a surface beneath a mold 120 with a liquid phase polyurethanemixture 712 filled cavity to generate a vacuum over the flat surfaceface 124 of mold 120. The reduced air pressure of the applied vacuumresults in bubbles 550 illustrated in prior figures being extracted fromthe liquid phase polyurethane mixture 712 in the cavity 122 of mold 120.The configuration illustrated in FIG. 8 for applying a vacuum to a mold120 may occur at different stages of the process and at differentpositions relative to the other components described herein, but in thepresent example occurs after the application of a dispersal mechanism138 and before application of a flexible blade 140.

Referring now to FIG. 9, a flexible blade 140 retained in a holder 142has removed excess liquid phase polyurethane mixture from the flatsurface face 124 of mold 120 and forced liquid phase polyurethanemixture into cavity 122 such that the only remaining liquid phasepolyurethane mixture 812 fills cavity 122. In the present example, avacuum has already removed bubbles from the liquid phase polyurethanemixture. As indicated by arrow 901, mold 120 has been retained in placewhile blade 140 has been moved across the face 124 of mold 120 indirection 901, which moves liquid phase polyurethane mixture in theopposite direction (relative to cavity 122) that dispersal mechanism 138previously moved the liquid phase polyurethane mixture. At this point,flexible blade 140 may be optionally cleaned by a cleaning mechanism tobe prepared for its next application on a subsequent mold.

While FIGS. 6-9 illustrate discrete events of application of liquidphase polyurethane mixture to a mold 120, dispersal of liquid phasepolyurethane mixture over a mold 120, and the removal of excess liquidphase polyurethane mixture from the flat surface face 124 of a mold 120and forcing liquid polyurethane into a cavity 122 of mold 120, theseneed not be totally discrete steps or portions of a system in accordancewith the present invention. For example, a dispersal mechanism 138 maybe distributing liquid phase polyurethane mixture at one portion of amold 120 while a nozzle 132 is still applying liquid phase polyurethanemixture to a flat surface face 124 of a mold 120. Further, a flexibleblade 140 may be forcing liquid phase polyurethane mixture into a cavity122 and removing excess liquid phase polyurethane mixture from a flatsurface face 124 of a mold 120 while a dispersal mechanism 138 is stilldispersing liquid phase polyurethane mixture across a flat surface face124 of a mold 120 and/or a dispensing mechanism 132 is still applyingliquid phase polyurethane mixture to another portion of a flat surfaceface 124 of a mold 120.

Referring now to FIG. 10, a method 1000 for forming cast polyurethane inaccordance with the present invention is illustrated. Method 1000 ismerely one example of an acceptable method in accordance with thepresent invention. Some steps of method 1000 illustrated in the presentexample may be omitted, while others may be performed in differentorders, and further steps may be added without departing from the scopeof the present invention. In step 1010, a mold with a flat surface faceand a cavity may be prepared for forming cast polyurethane and providedto a dispensing component. The mold provided in step 1010 may comprise amold made of aluminum or any other type of material. The mold providedin step 1010 may be cleaned and/or treated with a mold release materialto facilitate the ultimate removal of a cast polyurethane component.Further, the mold provided in step 1010 may be preheated or cooled, ifdesired, to provide optimal conditions for forming cast polyurethanefrom a liquid phase polyurethane mixture.

In step 1020 a liquid phase polyurethane mixture may be applied to theflat surface face of the mold. Any dispensing mechanism, some examplesof which are described herein, may be used in step 1020. The amount ofliquid phase polyurethane mixture dispensed in step 1020 may bemeasured, whether by weight or by volume, to provide a sufficient amountof liquid phase polyurethane mixture to fill a cavity on the moldprovided in step 1010, and the pattern in which the liquid phasepolyurethane mixture is dispensed may correspond to the cavity in themold.

The liquid phase polyurethane mixture applied to the flat surface faceof mold may be distributed in step 1030. Step 1030 may use an airblower, an air knife, vibrational unit, or another dispersal mechanismto spread the liquid phase polyurethane mixture over the flat face of amold to sufficiently engage a cavity of the mold corresponding to thecast polyurethane part ultimately to be formed by method 1000.Optionally, step 1030 may be eliminated, particularly if prior step 1020of applying liquid phase polyurethane mixture applies the liquid phasepolyurethane mixture with an adequate distribution over the flat surfaceface of a mold to appropriately and acceptably fill the cavity of themold provided in step 1010.

A vacuum may be applied to the liquid phase polyurethane mixture on amold to remove air bubbles from the liquid phase polyurethane mixture instep 1040. Step 1040 may involve creating an appropriately air-tightseal between a vacuum chamber and a mold and/or the surface beneath amold. The strength of the vacuum applied and the duration of applyingthe vacuum of step 1040 may vary based upon the quantity and size ofbubbles within the liquid phase polyurethane mixture, the qualitydesired for the cast polyurethane part, the amount of liquid phasepolyurethane mixture dispensed onto the mold, and the viscosity of theliquid phase polyurethane mixture dispensed.

In step 1050 excess liquid phase polyurethane mixture may be removedfrom the face of the mold, which may also ensure that liquid phasepolyurethane mixture is forced into all areas of a cavity or cavities ona mold. Step 1050 may be performed using a flexible blade, as describedherein. Further, a flexible blade used in performing step 1050 may becleaned at various intervals, such as after every use, after everysecond use, every five minutes of use, etc.

The polyurethane mixture may be further processed and/or cured to changeit from a liquid phase to a solid phase within the cavity of the mold instep 1060. The curing of step 1060 may involve the passage of time, theheating of a mold and/or the liquid phase polyurethane mixture within acavity of a form, manipulating the relative humidity around thepolyurethane mixture, etc. to obtain the desired physical properties ofthe polyurethane for use in a part for a shoe or another item. Anyoptional post processing performed in step 1060 may occur before,during, or after any curing of the polyurethane has occurred. Forexample, a textile may be joined to a partially cured polyurethane partusing a heat press to both enable the cast polyurethane to besubsequently removed from the mold more easily and to facilitate theintegration of the resulting cast polyurethane part into a larger item,such as a shoe upper.

The various steps of method 1000 may be performed by differentcomponents of a system, while some steps may be combined to be performedin a single step and/or by a single component of a system. A conveyancemechanism may move molds used in practicing method 1000 from onecomponent or station to another for the performance of various steps ofthe method 1000. More than one conveyance mechanism may be used in suchan example, and some steps of method 1000 may not involve a conveyancemechanism transporting a mold to a particular device, apparatus, orstation for performing that step. A mechanism may retain a mold in placefor a step of method 1000, or a step of method 1000 may be performedwhile a mold is in motion through a larger system. A computer systemexecuting instructions retained on computer readable media may controlvarious components may carry out methods in accordance with the presentinvention such as method 1000.

Referring now to FIG. 11, a further example for a flexible blade 1140and flexible blade holder 1142 is illustrated. As shown in FIG. 11, anarm 1190 may actuate flexible blade 1140 and holder 1142 vertically overa distance 1195 to allow flexible blade 1140 to engage a surface of amold 1120 by containing and moving across the flat surface face 1127 ofmold 1120. As explained previously, blade 1140 when actuated overdistance 1195 may engage mold 1120 by mold 1120 being moved towardsblade 1140, by blade 1140 being moved towards form 1120, or somecombination. In the example illustrated in FIG. 11, actuationcommunicated by arm 1190 may be accomplished using any type of mechanismor principal. Arm 1190 may further move flexible blade 1140 and holder1142 horizontally 1194 across the flat surface face 1124 of mold 1120retained in place by stopper 1106. After blade 1140 has been movedacross flat surface face 1124 of mold 1120 to remove any excess liquidpolyurethane, stopper 1106 may be withdrawn or released to permit mold1120 to be moved further by conveyance mechanism 1110.

Referring now to FIG. 12, an example of a vibrational unit 1200 that maybe used to disperse a liquid phase polyurethane mixture 1252 within acavity 1222 of a mold 1220. Vibrational unit 1200 may comprise a base1210 or other attachment mechanism that engages a mold 1220 and shakesor vibrates mold 1220 as indicated by arrows 1290. Any type of engine,motor, or other driving mechanism may be used by vibrational unit 1200to impart vibrations to base 1210 and, ultimately, to mold 1220 andliquid phase polyurethane mixture 1252. The vibrations of a vibrationalunit 1200 may occur in one, two, or three dimensions. A vibrational unit1200 may be used in conjunction with another dispersal mechanism orinstead of another dispersal mechanism. For example, a vibrational unit1200 may be used before, during, or after an air knife or air blowerdisperses the liquid phase polyurethane mixture 1252.

Referring now to FIG. 13, one example of a blade cleaning mechanism 1300is illustrated. A blade cleaning mechanism 1300 may be used to removeexcess liquid phase polyurethane mixture from a flexible blade 1140after use. Flexible blade 1140 may resemble that illustrated in theexample of FIG. 11, but other types of flexible blades may be cleaned bya mechanism 1300 in accordance with the present invention. While variousexamples of suitable flexible blade cleaning mechanisms have beendescribed above, the example shown in FIG. 13 is provided forillustrative purposes. Blade cleaning mechanism 1300 may be movedrelative to the flexible blade 1140 to be cleaned, although the flexibleblade 1140 may alternatively/additionally be moved towards the cleaningmechanism 1300. In the example shown in FIG. 13, a first air nozzle 1310dispenses a stream of arrow 1312 to remove excess liquid phasepolyurethane mixture from the flexible blade 1140. In the example ofFIG. 13, a second air nozzle 1320 may provide a second stream of arrow1322 to remove excess liquid phase polyurethane mixture from theopposite side of the flexible blade 1140 from the first air nozzle 1310.After the application of air streams from a first air nozzle 1310 and/ora second air nozzle 1320, a first rotating brush 1330 and/or a secondrotating brush 1340 may engage flexible blade 1140 while spinning asindicated by arrow 1332 and arrow 1342 to remove any remaining liquidphase polyurethane mixture from blade 1140 that was not removed by airstreams 1312, 1322. The cleaning mechanism 1300 illustrated in FIG. 13may be actuated towards and away from blade 1140 mechanically,pneumatically, or through any other process. Further, other examples ofblade cleaning mechanisms, some of which are described above, may beused in conjunction with the present invention.

Referring now to FIG. 14, the application of a sheet of material 1410using a press 1420 is illustrated. Sheet 1410 may comprise, for example,a knit or woven textile, a nonwoven textile, a film material, or anyother sheet of material that is desired to be affixed to the castpolyurethane 512 within cavity 122 of mold 120. Sheet 1410 may beadhered to polyurethane 512 using an adhesive and/or the flow propertiesof the polyurethane 512, depending upon the cure status of thepolyurethane 512. Press 1420 may comprise a heat press that applies bothheat and pressure to facilitate bonding. Affixing sheet 1410 topolyurethane 512 may be useful for later construction of a shoe or otheritem from the cast polyurethane 512, as well as to facilitate theextraction of the cast polyurethane 512 from the cavity 122 of mold 120.The application of a sheet 1410 using a press 1420 may particularlyoccur after polyurethane 512 has been partially cured, for example usinga heating table 1210 illustrated in FIG. 12.

While a specific example system and method in accordance with thepresent invention have been described herein, the present invention isnot limited to these specific examples. The present invention may beused with any desired formulation of polyurethane and to make anydesired part from cast polyurethane. Different materials for forms,flexible blades, and the like may be used, with some materials beingbetter suited to different formulations of polyurethane. Moreover,dispensing mechanisms, dispersal mechanisms, cleaning mechanisms, andthe like may vary based upon the particular demands and desires of aspecific application of the present invention.

What is claimed is:
 1. A system for forming cast polyurethane, thesystem comprising: a mold conveyance mechanism that conveys a mold withat least one cavity through the system during the forming of castpolyurethane, the at least one cavity within the mold extending below aflat surface face of the mold when the mold is maintained in asubstantially horizontal orientation during the process of forming castpolyurethane; a liquid phase polyurethane mixture dispensing system thatdeposits a predetermined amount of liquid phase polyurethane mixtureonto the flat surface face of the mold in a predetermined patterncorresponding to the at least one cavity within the mold when theconveyance mechanism positions the mold beneath the liquid phasepolyurethane mixture dispensing system; a vacuum system that applies avacuum to the liquid phase polyurethane mixture in the at least onecavity within the mold; and a flexible blade that contacts and movesacross the flat surface face of the mold after the conveyance mechanismhas moved the mold to the flexible blade, the flexible blade forcingliquid phase polyurethane into the cavities extending below the flatsurface face of the mold and removing excess liquid phase polyurethanemixture from the flat surface face of the mold.
 2. The system forforming cast polyurethane of claim 1, wherein the flexible bladecontacts and moves across the flat surface face of the mold after thevacuum system applies a vacuum to the liquid phase polyurethane mixture.3. The system for forming cast polyurethane of claim 1, wherein theflexible blade contacts and moves across the flat surface face of themold before the vacuum system applies a vacuum to the liquid phasepolyurethane mixture.
 4. The system for forming cast polyurethane ofclaim 1, further comprising a cleaning unit that removes liquid phasepolyurethane mixture from the flexible blade after the flexible bladehas contacted and moved across the flat surface face of the mold.
 5. Thesystem for forming cast polyurethane of claim 4, wherein the cleaningunit comprises a liquid jet.
 6. The system for forming cast polyurethaneof claim 4, wherein the cleaning unit physically contacts and wipes theflexible blade.
 7. The system for forming cast polyurethane of claim 4,wherein the cleaning unit comprises a chamber containing liquid in whichthe flexible blade is immersed.
 8. The system for forming castpolyurethane of claim 4, wherein the cleaning unit comprises anultrasonic vibration unit that vibrates the flexible blade.
 9. Thesystem for forming cast polyurethane of claim 1, wherein the moldconveyance mechanism transports comprises a system of rollers thatsupport a mold and at least one pusher that impart force to move themold along the rollers.
 10. The system for forming cast polyurethane ofclaim 1, wherein the mold conveyance mechanism comprises at least oneconveyor belt.
 11. A method for forming cast polyurethane, the methodcomprising: conveying a mold through a series of stations such that themold maintains a flat surface face substantially horizontal and facingupward while being conveyed, the mold having at least one cavityextending below the flat surface face; dispensing a predetermined amountof a liquid phase polyurethane mixture onto the flat surface face of themold in a predetermined configuration corresponding to the at least onecavity after the mold has been conveyed to a dispensing station;applying a vacuum to the liquid phase polyurethane mixture after theliquid phase polyurethane mixture has been dispersed onto the flatsurface face and into the at least one cavity when the mold is beneath avacuum system; and removing excess liquid phase polyurethane mixturefrom the flat surface face of the mold with a flexible blade thatcontacts and moves across the flat surface face after the vacuum hasbeen applied to the liquid phase polyurethane mixture.
 12. The systemfor forming cast polyurethane of claim 10, wherein the flexible blade ismaintained in position while the mold is moved by the conveyor belt tocause the flexible blade to contact and move across the flat surfaceface of the mold.
 13. The method for forming cast polyurethane of claim11, wherein removing excess liquid phase polyurethane mixture from theflat surface face of the mold comprises retaining the mold in placewhile moving the flexible blade to bring the flexible blade into contactwith the flat surface face and across the flat surface face.
 14. Themethod for forming cast polyurethane of claim 11, further comprisingcleaning the flexible blade after removing the excess liquid phasepolyurethane from the flat surface face of the mold.
 15. The method forforming cast polyurethane of claim 13, wherein removing excess liquidphase polyurethane from the flat surface face of the mold comprisesretaining the flexible blade in place while moving the mold to bring theflexible blade into contact with the flat surface face and across theflat surface face.